I have a 2000 Xterra 118,000 miles (190,000kms). About a week ago, it stalled in a parking lot after starting. After a couple of times doing this, I took it in and mechanic is stumped by lack of codes. Only a knock sensor. There is no check engine light. Got the car back for a week with nothing unusual happening. Feeling optomistic it was just bad gas or something, stalled again. Today is bad and now in the driveway, can't get it started anymore. It deteriorated very quickly today. It will fire, run really roughly then die. On subsequent starts, it won't catch. In the last few days, I have noticed that the rpms after start initially go to about 1800 then drop to 1500 then 1000 then to 800 after a few seconds. Today, it just drops below 800 immediately then dies. At one point, when trying to hold a steady idle, the rpms fluctuated about 200 rpms before stabilizing. Now, it won't start at all in the driveway. I have read a lot of threads and internet stuff and there is talk of cam sensors, MAF sensors, fuel pumps, etc. What does a distributor failure look like. Should that be place number one to start since there are no codes?

Thanks

Andrew

The distributors bearing goes out. Remove the cap, remove the rotor, remove the tone ring and sensor, remove the rest of the internal guts and covers. Then at the bottom you should find a sealed roller bearing. This bearing should be in good condition. If you see that it has play or has chunks of black stuff at the bottom its definitely bad. Though some people have also had issues with the electronics end of it inspecting the bearing is a good start.

Couldn't he just pull the distributor out and check the shaft for play?

To me, it sounds like a MAF problem, or a massive vacuum leak.

This vacuum leak usually is more apparent on the uphills.

Does it sound different?

Try starting your Xterra, pulling the MAF plug, turn the truck off, turn the key to the ON position, plug your MAF back in, start.

I tried the MAP suggestion and this is what happened - The car started fine this morning but idled a little high in my opinion. But it started normally. I yanked the MAF and the truck died instantly. I turned the car off then back on, plugged in the MAF and the start did it's usual rough idle and quit. Is this indicitive of a MAF problem?

Nope, sounds more like the distributor taking a dump or a fuel problem.

Thanks for the help so far. The only thing I don't get is that is only a starting problem. Once the car starts, it's fine. It doesn't stall at lights, etc and it has never left me at the side of the road. It's only when the car is turned off and then a re-start is attempted that it acts up. Usually leaving it for a while does the trick to get it started and then it goes fine until the next time it's turned off. A distributor won't do that, will it?

Hmmmmm. There are a ton of things that can do that. The simplest one is a dirty air filter.

Hmmmmm. There are a ton of things that can do that. The simplest one is a dirty air filter.

We have air filters!??!?

:mocking:

Took the truck to my mechanic today and since there are no codes except Knock sensor, he's stumped. He thinks the MAF sensor should be ok. He had a look at the dist and it looked ok. He's thinking of replacing the knock sensor tomorrow. It's a 4 hr job and a 250 dollar part. It scares me a little because I havn't seen too many people saying that the knock sensor is a big deal. Would it cause the car to run roughly on a start and work sometimes and not others? Should I call him tomorrow morning and tell him to hold off. I don't want to pay $1000 for something that probably won't be the problem. Any thoughts?

Found the problem. The wiring harness on top of the fuel tank that connects to the fuel pump was badly corroded. The mechanic went through the back seat to the top of the tank and replaced the wiring harness to the pump. He had to make his own instead of replacing the whole pump. Fixed!

forget the k/s.

there was a recall on that...you might be able to go to the dealer and have them swap it and tell them that you had it fixed because it was an emergency. just make sure you are in the state that the recall allows for.

http://www.lemonauto.com/complaints/nissan/xterra.htm

Necro much?

BTW, while this is revived...if your mechanic was "stumped" by a lack of codes, get a new mechanic. Any mechanic who relies solely on the computer to diagnose engine problems isn't a mechanic.

I had the same problem, no check engine lights just the knock sensor code. It would run fine when it was cold, but when it warmed up it would start missing extremely bad and sometimes die. At one point it wouldn't go over 1500rpms no matter how much you laid into the gas. Tried the Throttle position sensor, didn't help. Talked to a mechanic and he said it was a bad distributor right off the bat. I tried pulling off ever plug wire at the cap on at a time, and things seemed to be working correctly. I turned out it was the distributor, let me know if anyone else has this problem and I can explain the symptems that I had better to hopefully help you in diagnosing your problems.

I could see that, actually. If the bearing or gear is bad for example, it may not be able to keep up with the increased RPM and start to miss or go off center.

I had the same problem, no check engine lights just the knock sensor code. It would run fine when it was cold, but when it warmed up it would start missing extremely bad and sometimes die. At one point it wouldn't go over 1500rpms no matter how much you laid into the gas. Tried the Throttle position sensor, didn't help. Talked to a mechanic and he said it was a bad distributor right off the bat. I tried pulling off ever plug wire at the cap on at a time, and things seemed to be working correctly. I turned out it was the distributor, let me know if anyone else has this problem and I can explain the symptems that I had better to hopefully help you in diagnosing your problems.

That is the distributor going south.